1/*
2 * DECnet       An implementation of the DECnet protocol suite for the LINUX
3 *              operating system.  DECnet is implemented using the  BSD Socket
4 *              interface as the means of communication with the user level.
5 *
6 *              DECnet Routing Forwarding Information Base (Routing Tables)
7 *
8 * Author:      Steve Whitehouse <SteveW@ACM.org>
9 *              Mostly copied from the IPv4 routing code
10 *
11 *
12 * Changes:
13 *
14 */
15#include <linux/config.h>
16#include <linux/string.h>
17#include <linux/net.h>
18#include <linux/socket.h>
19#include <linux/sockios.h>
20#include <linux/init.h>
21#include <linux/skbuff.h>
22#include <linux/netlink.h>
23#include <linux/rtnetlink.h>
24#include <linux/proc_fs.h>
25#include <linux/netdevice.h>
26#include <linux/timer.h>
27#include <linux/spinlock.h>
28#include <asm/atomic.h>
29#include <asm/uaccess.h>
30#include <linux/route.h> /* RTF_xxx */
31#include <net/neighbour.h>
32#include <net/dst.h>
33#include <net/dn.h>
34#include <net/dn_route.h>
35#include <net/dn_fib.h>
36#include <net/dn_neigh.h>
37#include <net/dn_dev.h>
38
39struct dn_zone
40{
41	struct dn_zone		*dz_next;
42	struct dn_fib_node 	**dz_hash;
43	int			dz_nent;
44	int			dz_divisor;
45	u32			dz_hashmask;
46#define DZ_HASHMASK(dz)	((dz)->dz_hashmask)
47	int			dz_order;
48	u32			dz_mask;
49#define DZ_MASK(dz)	((dz)->dz_mask)
50};
51
52struct dn_hash
53{
54	struct dn_zone	*dh_zones[17];
55	struct dn_zone	*dh_zone_list;
56};
57
58#define dz_key_0(key)		((key).datum = 0)
59#define dz_prefix(key,dz)	((key).datum)
60
61#define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
62        for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
63
64#define endfor_nexthops(fi) }
65
66#define DN_MAX_DIVISOR 1024
67#define DN_S_ZOMBIE 1
68#define DN_S_ACCESSED 2
69
70#define DN_FIB_SCAN(f, fp) \
71for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
72
73#define DN_FIB_SCAN_KEY(f, fp, key) \
74for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
75
76
77static rwlock_t dn_fib_tables_lock = RW_LOCK_UNLOCKED;
78static struct dn_fib_table *dn_fib_tables[DN_NUM_TABLES + 1];
79
80static kmem_cache_t *dn_hash_kmem;
81static int dn_fib_hash_zombies;
82
83static __inline__ dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
84{
85	u32 h = ntohs(key.datum)>>(16 - dz->dz_order);
86	h ^= (h >> 10);
87	h ^= (h >> 6);
88	h ^= (h >> 3);
89	h &= DZ_HASHMASK(dz);
90	return *(dn_fib_idx_t *)&h;
91}
92
93static __inline__ dn_fib_key_t dz_key(u16 dst, struct dn_zone *dz)
94{
95	dn_fib_key_t k;
96	k.datum = dst & DZ_MASK(dz);
97	return k;
98}
99
100static __inline__ struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
101{
102	return &dz->dz_hash[dn_hash(key, dz).datum];
103}
104
105static __inline__ struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
106{
107	return dz->dz_hash[dn_hash(key, dz).datum];
108}
109
110static __inline__ int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
111{
112	return a.datum == b.datum;
113}
114
115static __inline__ int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
116{
117	return a.datum <= b.datum;
118}
119
120static __inline__ void dn_rebuild_zone(struct dn_zone *dz,
121					struct dn_fib_node **old_ht,
122					int old_divisor)
123{
124	int i;
125	struct dn_fib_node *f, **fp, *next;
126
127	for(i = 0; i < old_divisor; i++) {
128		for(f = old_ht[i]; f; f = f->fn_next) {
129			next = f->fn_next;
130			for(fp = dn_chain_p(f->fn_key, dz);
131				*fp && dn_key_leq((*fp)->fn_key, f->fn_key);
132				fp = &(*fp)->fn_next)
133				/* NOTHING */;
134			f->fn_next = *fp;
135			*fp = f;
136		}
137	}
138}
139
140static void dn_rehash_zone(struct dn_zone *dz)
141{
142	struct dn_fib_node **ht, **old_ht;
143	int old_divisor, new_divisor;
144	u32 new_hashmask;
145
146	old_divisor = dz->dz_divisor;
147
148	switch(old_divisor) {
149		case 16:
150			new_divisor = 256;
151			new_hashmask = 0xFF;
152			break;
153		default:
154			printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n", old_divisor);
155		case 256:
156			new_divisor = 1024;
157			new_hashmask = 0x3FF;
158			break;
159	}
160
161	ht = kmalloc(new_divisor*sizeof(struct dn_fib_node*), GFP_KERNEL);
162
163	if (ht == NULL)
164		return;
165
166	memset(ht, 0, new_divisor*sizeof(struct dn_fib_node *));
167	write_lock_bh(&dn_fib_tables_lock);
168	old_ht = dz->dz_hash;
169	dz->dz_hash = ht;
170	dz->dz_hashmask = new_hashmask;
171	dz->dz_divisor = new_divisor;
172	dn_rebuild_zone(dz, old_ht, old_divisor);
173	write_unlock_bh(&dn_fib_tables_lock);
174	kfree(old_ht);
175}
176
177static void dn_free_node(struct dn_fib_node *f)
178{
179	dn_fib_release_info(DN_FIB_INFO(f));
180	kmem_cache_free(dn_hash_kmem, f);
181}
182
183
184static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
185{
186	int i;
187	struct dn_zone *dz = kmalloc(sizeof(struct dn_zone), GFP_KERNEL);
188	if (!dz)
189		return NULL;
190
191	memset(dz, 0, sizeof(struct dn_zone));
192	if (z) {
193		dz->dz_divisor = 16;
194		dz->dz_hashmask = 0x0F;
195	} else {
196		dz->dz_divisor = 1;
197		dz->dz_hashmask = 0;
198	}
199
200	dz->dz_hash = kmalloc(dz->dz_divisor*sizeof(struct dn_fib_node *), GFP_KERNEL);
201
202	if (!dz->dz_hash) {
203		kfree(dz);
204		return NULL;
205	}
206
207	memset(dz->dz_hash, 0, dz->dz_divisor*sizeof(struct dn_fib_node*));
208	dz->dz_order = z;
209	dz->dz_mask = dnet_make_mask(z);
210
211	for(i = z + 1; i <= 16; i++)
212		if (table->dh_zones[i])
213			break;
214
215	write_lock_bh(&dn_fib_tables_lock);
216	if (i>16) {
217		dz->dz_next = table->dh_zone_list;
218		table->dh_zone_list = dz;
219	} else {
220		dz->dz_next = table->dh_zones[i]->dz_next;
221		table->dh_zones[i]->dz_next = dz;
222	}
223	table->dh_zones[z] = dz;
224	write_unlock_bh(&dn_fib_tables_lock);
225	return dz;
226}
227
228
229static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
230{
231	struct rtnexthop *nhp;
232	int nhlen;
233
234	if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
235		return 1;
236
237	if (rta->rta_oif || rta->rta_gw) {
238		if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
239		    (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
240			return 0;
241		return 1;
242	}
243
244	if (rta->rta_mp == NULL)
245		return 0;
246
247	nhp = RTA_DATA(rta->rta_mp);
248	nhlen = RTA_PAYLOAD(rta->rta_mp);
249
250	for_nexthops(fi) {
251		int attrlen = nhlen - sizeof(struct rtnexthop);
252		dn_address gw;
253
254		if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
255			return -EINVAL;
256		if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
257			return 1;
258		if (attrlen) {
259			gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
260
261			if (gw && gw != nh->nh_gw)
262				return 1;
263		}
264		nhp = RTNH_NEXT(nhp);
265	} endfor_nexthops(fi);
266
267	return 0;
268}
269
270static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
271                        u8 tb_id, u8 type, u8 scope, void *dst, int dst_len,
272                        struct dn_fib_info *fi)
273{
274        struct rtmsg *rtm;
275        struct nlmsghdr *nlh;
276        unsigned char *b = skb->tail;
277
278        nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*rtm));
279        rtm = NLMSG_DATA(nlh);
280        rtm->rtm_family = AF_DECnet;
281        rtm->rtm_dst_len = dst_len;
282        rtm->rtm_src_len = 0;
283        rtm->rtm_tos = 0;
284        rtm->rtm_table = tb_id;
285        rtm->rtm_flags = fi->fib_flags;
286        rtm->rtm_scope = scope;
287	rtm->rtm_type  = type;
288        if (rtm->rtm_dst_len)
289                RTA_PUT(skb, RTA_DST, 2, dst);
290        rtm->rtm_protocol = fi->fib_protocol;
291        if (fi->fib_priority)
292                RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
293        if (fi->fib_nhs == 1) {
294                if (fi->fib_nh->nh_gw)
295                        RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
296                if (fi->fib_nh->nh_oif)
297                        RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
298        }
299        if (fi->fib_nhs > 1) {
300                struct rtnexthop *nhp;
301                struct rtattr *mp_head;
302                if (skb_tailroom(skb) <= RTA_SPACE(0))
303                        goto rtattr_failure;
304                mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
305
306                for_nexthops(fi) {
307                        if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
308                                goto rtattr_failure;
309                        nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
310                        nhp->rtnh_flags = nh->nh_flags & 0xFF;
311                        nhp->rtnh_hops = nh->nh_weight - 1;
312                        nhp->rtnh_ifindex = nh->nh_oif;
313                        if (nh->nh_gw)
314                                RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
315                        nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
316                } endfor_nexthops(fi);
317                mp_head->rta_type = RTA_MULTIPATH;
318                mp_head->rta_len = skb->tail - (u8*)mp_head;
319        }
320
321        nlh->nlmsg_len = skb->tail - b;
322        return skb->len;
323
324
325nlmsg_failure:
326rtattr_failure:
327        skb_trim(skb, b - skb->data);
328        return -1;
329}
330
331
332static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, int tb_id,
333                        struct nlmsghdr *nlh, struct netlink_skb_parms *req)
334{
335        struct sk_buff *skb;
336        u32 pid = req ? req->pid : 0;
337        int size = NLMSG_SPACE(sizeof(struct rtmsg) + 256);
338
339        skb = alloc_skb(size, GFP_KERNEL);
340        if (!skb)
341                return;
342
343        if (dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
344                                f->fn_type, f->fn_scope, &f->fn_key, z,
345                                DN_FIB_INFO(f)) < 0) {
346                kfree_skb(skb);
347                return;
348        }
349        NETLINK_CB(skb).dst_groups = RTMGRP_DECnet_ROUTE;
350        if (nlh->nlmsg_flags & NLM_F_ECHO)
351                atomic_inc(&skb->users);
352        netlink_broadcast(rtnl, skb, pid, RTMGRP_DECnet_ROUTE, GFP_KERNEL);
353        if (nlh->nlmsg_flags & NLM_F_ECHO)
354                netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
355}
356
357static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
358				struct netlink_callback *cb,
359				struct dn_fib_table *tb,
360				struct dn_zone *dz,
361				struct dn_fib_node *f)
362{
363	int i, s_i;
364
365	s_i = cb->args[3];
366	for(i = 0; f; i++, f = f->fn_next) {
367		if (i < s_i)
368			continue;
369		if (f->fn_state & DN_S_ZOMBIE)
370			continue;
371		if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
372				cb->nlh->nlmsg_seq,
373				RTM_NEWROUTE,
374				tb->n,
375				(f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
376				f->fn_scope, &f->fn_key, dz->dz_order,
377				f->fn_info) < 0) {
378			cb->args[3] = i;
379			return -1;
380		}
381	}
382	cb->args[3] = i;
383	return skb->len;
384}
385
386static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
387				struct netlink_callback *cb,
388				struct dn_fib_table *tb,
389				struct dn_zone *dz)
390{
391	int h, s_h;
392
393	s_h = cb->args[2];
394	for(h = 0; h < dz->dz_divisor; h++) {
395		if (h < s_h)
396			continue;
397		if (h > s_h)
398			memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
399		if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
400			continue;
401		if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
402			cb->args[2] = h;
403			return -1;
404		}
405	}
406	cb->args[2] = h;
407	return skb->len;
408}
409
410static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
411                                struct netlink_callback *cb)
412{
413        int m, s_m;
414	struct dn_zone *dz;
415	struct dn_hash *table = (struct dn_hash *)tb->data;
416
417	s_m = cb->args[1];
418	read_lock(&dn_fib_tables_lock);
419	for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
420		if (m < s_m)
421			continue;
422		if (m > s_m)
423			memset(&cb->args[2], 0, sizeof(cb->args) - 2*sizeof(cb->args[0]));
424
425		if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
426			cb->args[1] = m;
427			read_unlock(&dn_fib_tables_lock);
428			return -1;
429		}
430	}
431	read_unlock(&dn_fib_tables_lock);
432	cb->args[1] = m;
433
434        return skb->len;
435}
436
437static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
438{
439	struct dn_hash *table = (struct dn_hash *)tb->data;
440	struct dn_fib_node *new_f, *f, **fp, **del_fp;
441	struct dn_zone *dz;
442	struct dn_fib_info *fi;
443        int z = r->rtm_dst_len;
444	int type = r->rtm_type;
445	dn_fib_key_t key;
446        int err;
447
448        if (z > 16)
449                return -EINVAL;
450
451	dz = table->dh_zones[z];
452	if (!dz && !(dz = dn_new_zone(table, z)))
453		return -ENOBUFS;
454
455	dz_key_0(key);
456	if (rta->rta_dst) {
457		dn_address dst;
458		memcpy(&dst, rta->rta_dst, 2);
459		if (dst & ~DZ_MASK(dz))
460			return -EINVAL;
461		key = dz_key(dst, dz);
462	}
463
464        if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
465                return err;
466
467	if (dz->dz_nent > (dz->dz_divisor << 2) &&
468			dz->dz_divisor > DN_MAX_DIVISOR &&
469			(z==16 || (1<<z) > dz->dz_divisor))
470		dn_rehash_zone(dz);
471
472	fp = dn_chain_p(key, dz);
473
474	DN_FIB_SCAN(f, fp) {
475		if (dn_key_leq(key, f->fn_key))
476			break;
477	}
478
479	del_fp = NULL;
480
481	if (f && (f->fn_state & DN_S_ZOMBIE) &&
482			dn_key_eq(f->fn_key, key)) {
483		del_fp = fp;
484		fp = &f->fn_next;
485		f = *fp;
486		goto create;
487	}
488
489	DN_FIB_SCAN_KEY(f, fp, key) {
490		if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
491			break;
492	}
493
494	if (f && dn_key_eq(f->fn_key, key) &&
495			fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
496		struct dn_fib_node **ins_fp;
497
498		err = -EEXIST;
499		if (n->nlmsg_flags & NLM_F_EXCL)
500			goto out;
501
502		if (n->nlmsg_flags & NLM_F_REPLACE) {
503			del_fp = fp;
504			fp = &f->fn_next;
505			f = *fp;
506			goto replace;
507		}
508
509		ins_fp = fp;
510		err = -EEXIST;
511
512		DN_FIB_SCAN_KEY(f, fp, key) {
513			if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
514				break;
515			if (f->fn_type == type && f->fn_scope == r->rtm_scope
516					&& DN_FIB_INFO(f) == fi)
517				goto out;
518		}
519
520		if (!(n->nlmsg_flags & NLM_F_APPEND)) {
521			fp = ins_fp;
522			f = *fp;
523		}
524	}
525
526create:
527	err = -ENOENT;
528	if (!(n->nlmsg_flags & NLM_F_CREATE))
529		goto out;
530
531replace:
532	err = -ENOBUFS;
533	new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL);
534	if (new_f == NULL)
535		goto out;
536
537	memset(new_f, 0, sizeof(struct dn_fib_node));
538
539	new_f->fn_key = key;
540	new_f->fn_type = type;
541	new_f->fn_scope = r->rtm_scope;
542	DN_FIB_INFO(new_f) = fi;
543
544	new_f->fn_next = f;
545	write_lock_bh(&dn_fib_tables_lock);
546	*fp = new_f;
547	write_unlock_bh(&dn_fib_tables_lock);
548	dz->dz_nent++;
549
550	if (del_fp) {
551		f = *del_fp;
552		write_lock_bh(&dn_fib_tables_lock);
553		*del_fp = f->fn_next;
554		write_unlock_bh(&dn_fib_tables_lock);
555
556		if (!(f->fn_state & DN_S_ZOMBIE))
557			dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
558		if (f->fn_state & DN_S_ACCESSED)
559			dn_rt_cache_flush(-1);
560		dn_free_node(f);
561		dz->dz_nent--;
562	} else {
563		dn_rt_cache_flush(-1);
564	}
565
566        dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
567
568        return 0;
569out:
570	dn_fib_release_info(fi);
571	return err;
572}
573
574
575static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
576{
577	struct dn_hash *table = (struct dn_hash*)tb->data;
578	struct dn_fib_node **fp, **del_fp, *f;
579        int z = r->rtm_dst_len;
580	struct dn_zone *dz;
581	dn_fib_key_t key;
582	int matched;
583
584
585        if (z > 16)
586                return -EINVAL;
587
588	if ((dz = table->dh_zones[z]) == NULL)
589		return -ESRCH;
590
591	dz_key_0(key);
592	if (rta->rta_dst) {
593		dn_address dst;
594		memcpy(&dst, rta->rta_dst, 2);
595		if (dst & ~DZ_MASK(dz))
596			return -EINVAL;
597		key = dz_key(dst, dz);
598	}
599
600	fp = dn_chain_p(key, dz);
601
602	DN_FIB_SCAN(f, fp) {
603		if (dn_key_eq(f->fn_key, key))
604			break;
605		if (dn_key_leq(key, f->fn_key))
606			return -ESRCH;
607	}
608
609	matched = 0;
610	del_fp = NULL;
611	DN_FIB_SCAN_KEY(f, fp, key) {
612		struct dn_fib_info *fi = DN_FIB_INFO(f);
613
614		if (f->fn_state & DN_S_ZOMBIE)
615			return -ESRCH;
616
617		matched++;
618
619		if (del_fp == NULL &&
620				(!r->rtm_type || f->fn_type == r->rtm_type) &&
621				(r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
622				(!r->rtm_protocol ||
623					fi->fib_protocol == r->rtm_protocol) &&
624				dn_fib_nh_match(r, n, rta, fi) == 0)
625			del_fp = fp;
626	}
627
628	if (del_fp) {
629		f = *del_fp;
630        	dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
631
632		if (matched != 1) {
633			write_lock_bh(&dn_fib_tables_lock);
634			*del_fp = f->fn_next;
635			write_unlock_bh(&dn_fib_tables_lock);
636
637			if (f->fn_state & DN_S_ACCESSED)
638				dn_rt_cache_flush(-1);
639			dn_free_node(f);
640			dz->dz_nent--;
641		} else {
642			f->fn_state |= DN_S_ZOMBIE;
643			if (f->fn_state & DN_S_ACCESSED) {
644				f->fn_state &= ~DN_S_ACCESSED;
645				dn_rt_cache_flush(-1);
646			}
647			if (++dn_fib_hash_zombies > 128)
648				dn_fib_flush();
649		}
650
651		return 0;
652	}
653
654        return -ESRCH;
655}
656
657static __inline__ int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
658{
659	int found = 0;
660	struct dn_fib_node *f;
661
662	while((f = *fp) != NULL) {
663		struct dn_fib_info *fi = DN_FIB_INFO(f);
664
665		if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
666			write_lock_bh(&dn_fib_tables_lock);
667			*fp = f->fn_next;
668			write_unlock_bh(&dn_fib_tables_lock);
669
670			dn_free_node(f);
671			found++;
672			continue;
673		}
674		fp = &f->fn_next;
675	}
676
677	return found;
678}
679
680static int dn_fib_table_flush(struct dn_fib_table *tb)
681{
682	struct dn_hash *table = (struct dn_hash *)tb->data;
683	struct dn_zone *dz;
684	int found = 0;
685
686	dn_fib_hash_zombies = 0;
687	for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
688		int i;
689		int tmp = 0;
690		for(i = dz->dz_divisor-1; i >= 0; i--)
691			tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
692		dz->dz_nent -= tmp;
693		found += tmp;
694	}
695
696	return found;
697}
698
699static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct dn_fib_key *
700key, struct dn_fib_res *res)
701{
702        int err;
703	struct dn_zone *dz;
704	struct dn_hash *t = (struct dn_hash *)tb->data;
705
706	read_lock(&dn_fib_tables_lock);
707	for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
708		struct dn_fib_node *f;
709		dn_fib_key_t k = dz_key(key->dst, dz);
710
711		for(f = dz_chain(k, dz); f; f = f->fn_next) {
712			if (!dn_key_leq(k, f->fn_key))
713				break;
714			else
715				continue;
716
717			f->fn_state |= DN_S_ACCESSED;
718
719			if (f->fn_state&DN_S_ZOMBIE)
720				continue;
721			if (f->fn_scope < key->scope)
722				continue;
723
724			err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), key, res);
725			if (err == 0) {
726				res->type = f->fn_type;
727				res->scope = f->fn_scope;
728				res->prefixlen = dz->dz_order;
729				goto out;
730			}
731			if (err < 0)
732				goto out;
733		}
734	}
735	err = 1;
736out:
737	read_unlock(&dn_fib_tables_lock);
738        return err;
739}
740
741#ifdef CONFIG_PROC_FS
742
743static unsigned dn_fib_flag_trans(int type, int dead, u16 mask, struct dn_fib_info *fi)
744{
745	static unsigned type2flags[RTN_MAX+1] = {
746		0, 0, 0, 0, 0, 0, 0, RTF_REJECT, RTF_REJECT, 0, 0, 0
747	};
748	unsigned flags = type2flags[type];
749
750	if (fi && fi->fib_nh->nh_gw)
751		flags |= RTF_GATEWAY;
752	if (mask == 0xFFFF)
753		flags |= RTF_HOST;
754	if (dead)
755		flags |= RTF_UP;
756	return flags;
757}
758
759static void dn_fib_node_get_info(int type, int dead, struct dn_fib_info *fi, u16 prefix, u16 mask, char *buffer)
760{
761	int len;
762	unsigned flags = dn_fib_flag_trans(type, dead, mask, fi);
763
764	if (fi) {
765		len = sprintf(buffer, "%s\t%04x\t%04x\t%04x\t%d\t%u\t%d\t%04x\t%d\t%u\t%u",
766				fi->fib_dev ? fi->fib_dev->name : "*", prefix,
767				fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
768				mask, 0, 0, 0);
769	} else {
770		len = sprintf(buffer, "*\t%04x\t%04x\t%04x\t%d\t%u\t%d\t%04x\t%d\t%u\t%u",
771					prefix, 0,
772					flags, 0, 0, 0,
773					mask, 0, 0, 0);
774	}
775	memset(buffer+len, ' ', 127-len);
776	buffer[127] = '\n';
777}
778
779static int dn_fib_table_get_info(struct dn_fib_table *tb, char *buffer, int first, int count)
780{
781	struct dn_hash *table = (struct dn_hash *)tb->data;
782	struct dn_zone *dz;
783	int pos = 0;
784	int n = 0;
785
786	read_lock(&dn_fib_tables_lock);
787	for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
788		int i;
789		struct dn_fib_node *f;
790		int maxslot = dz->dz_divisor;
791		struct dn_fib_node **fp = dz->dz_hash;
792
793		if (dz->dz_nent == 0)
794			continue;
795
796		if (pos + dz->dz_nent < first) {
797			pos += dz->dz_nent;
798			continue;
799		}
800
801		for(i = 0; i < maxslot; i++, fp++) {
802			for(f = *fp; f ; f = f->fn_next) {
803				if (++pos <= first)
804					continue;
805				dn_fib_node_get_info(f->fn_type,
806						f->fn_state & DN_S_ZOMBIE,
807						DN_FIB_INFO(f),
808						dz_prefix(f->fn_key, dz),
809						DZ_MASK(dz), buffer);
810				buffer += 128;
811				if (++n >= count)
812					goto out;
813			}
814		}
815	}
816out:
817	read_unlock(&dn_fib_tables_lock);
818	return n;
819}
820#endif /* CONFIG_PROC_FS */
821
822struct dn_fib_table *dn_fib_get_table(int n, int create)
823{
824        struct dn_fib_table *t;
825
826        if (n < DN_MIN_TABLE)
827                return NULL;
828
829        if (n > DN_NUM_TABLES)
830                return NULL;
831
832        if (dn_fib_tables[n])
833                return dn_fib_tables[n];
834
835        if (!create)
836                return NULL;
837
838        if (in_interrupt() && net_ratelimit()) {
839                printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table
840from interrupt\n");
841                return NULL;
842        }
843        if ((t = kmalloc(sizeof(struct dn_fib_table), GFP_KERNEL)) == NULL)
844                return NULL;
845
846        memset(t, 0, sizeof(struct dn_fib_table));
847
848        t->n = n;
849        t->insert = dn_fib_table_insert;
850        t->delete = dn_fib_table_delete;
851        t->lookup = dn_fib_table_lookup;
852        t->flush  = dn_fib_table_flush;
853#ifdef CONFIG_PROC_FS
854	t->get_info = dn_fib_table_get_info;
855#endif
856        t->dump = dn_fib_table_dump;
857        dn_fib_tables[n] = t;
858
859        return t;
860}
861
862static void dn_fib_del_tree(int n)
863{
864        struct dn_fib_table *t;
865
866        write_lock(&dn_fib_tables_lock);
867        t = dn_fib_tables[n];
868        dn_fib_tables[n] = NULL;
869        write_unlock(&dn_fib_tables_lock);
870
871        if (t) {
872                kfree(t);
873        }
874}
875
876struct dn_fib_table *dn_fib_empty_table(void)
877{
878        int id;
879
880        for(id = DN_MIN_TABLE; id <= DN_NUM_TABLES; id++)
881                if (dn_fib_tables[id] == NULL)
882                        return dn_fib_get_table(id, 1);
883        return NULL;
884}
885
886void __init dn_fib_table_init(void)
887{
888	dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
889					sizeof(struct dn_fib_info),
890					0, SLAB_HWCACHE_ALIGN,
891					NULL, NULL);
892}
893
894void __exit dn_fib_table_cleanup(void)
895{
896	int i;
897
898	for (i = 0; i < DN_NUM_TABLES + 1; ++i)
899		dn_fib_del_tree(i);
900
901	return;
902}
903